@mixin prefix($property, $value, $prefixes) {
    @each $prefix in $prefixes {
        -#{$prefix}-#{$property}: $value;
    }
    #{$property}: $value;
}

.gray {
    @include prefix(filter, grayscale(10%), moz webkit);
}

@mixin corner-icon($name, $top-or-bottom, $left-or-right) {
    .icon-#{$name} {
        background-image: url('/icons/#{$name}.svg');
        position: absolute;
        #{$top-or-bottom}: 0;
        #{$left-or-right}: 0;
    }
}

@include corner-icon('mail', top, left);
